1. Field of the Invention
The present invention relates to a grommet attached to an electric connection box made of a conductive metal plate such as an iron plate, a stainless plate and the like, and a structure for taking out an electric power from an electric connection box by using the grommet.
2. Description of the Related Art
In a structure for taking out an electric power from an electric connection box in accordance with the related art, a wall portion thereof is made of a conductive metal plate such as an iron plate, a stainless plate and the like.
In the structure, a mounting hole is formed on the wall portion of the electric connection box and a grommet made of an insulating material is fitted into the mounting hole. A coated electric wire is inserted into the grommet and a screwing terminal is connected to an end portion of an outer side of the electric connection box in the coated electric wire. An end portion of the coated electric wire close to the inner portion of the electric connection box is connected to a bus bar disposed within the electric connection box, so that an electric power can be taken out by connecting a terminal portion of the screwing terminal to the other electric wire by means of screwing.
In a structure in accordance with another related art, a connector is attached to the wall portion of the electric connection box. The terminal portion is drawn out within the electric connection box from the connector, and the terminal portion is disposed within the electric connection box so as to be connected to the bus bar constituting a branch circuit by means of a bolt, so that the electric power is taken out.
In order to extend an electric wire through a vehicle body panel by using a grommet, in a structure described in Japanese Patent Unexamined Application Laid Open No. 7-296660, the grommet is formed as a trumpet shape by using an insulating material and a fitting groove is formed on an outer peripheral surface thereof. In a state that the electric wire is extended through the grommet, the grommet is pressed into a through hole of the panel and the fitting groove is fitted into the through hole, so that the electric wire is disposed in such a manner as to extend through the panel.
In the former structure, it is necessary to support a connection portion between the terminal portion of the screwing terminal and the other electric wire by a holder, however, there is a problem that it is difficult to dispose the holder in a narrow vehicle inner space. Further, it is difficult to bend the electric wire within the narrow space and a degree of freedom for disposing the electric wire is limited. In the latter structure, the matter is the same as that of the former structure, that is, since the connector itself is large, it is difficult to dispose the connector within the narrow vehicle inner space. Further, in the structure described in Japanese Patent Unexamined Application Laid Open No. 7-296660, since the grommet is used, there are the same problems as those mentioned above.
Further, in the conventional three structures mentioned above, since the electric power is taken out by using the electric wire or the connector and the connection to the bus bar within the electric connection box is performed, an end treatment with respect to these elements is required, so that the operation is troublesome.
Taking the above matter into consideration, it is considered that in order to form the branch circuit, the bus bar disposed within the electric connection box is drawn out from the electric connection box so as to take out the electric power. However, in this case, it is necessary to secure an insulation between the bus bar and the electric connection box. In order to achieve this, it is necessary to provide an insulation distance equal to or more than 15 mm between the elements, and it is not practical to secure such a long insulation distance within the narrow space.